Three new metal–organic complexes, [CoL2(H2O)4] 1, [CdL2(H2O)2] 2, and [CuL2(H2O)2] 3 [HL = 4-chlorophenyloxyacetic acid], have been synthesized and characterized by IR spectra, elemental analysis, fluorescence spectra, and single-crystal X-ray diffraction. Compounds 1, 2, and 3 are all zero-dimensional dimers. The carboxylate ligand exhibits different coordination modes in all compounds. These compounds exhibit interesting supramolecular architecture according to O–H···O and C–H···Cl interactions. Compounds 1, 2, and 3 develop to different framework though they all are from same ligands, which will be helpful to design of different materials.
[Supplemental materials are available for this article. Go to the publisher's online edition of Molecular Crystals and Liquid Crystals to view the free supplemental file: CCDC 902676, 902674, 902675 contains the supplementary crystallographic data for this article. These data can be obtained free of charge viawww.ccdc.cam.ac.uk/conts/retrieving.html(or from the Cambridge Crystallographic Data Centre, 12, Union Road, Cambridge CB2 1EZ, UK; Fax: C44 1223 336033; e-mail: deposit@ccdc.cam.ac.uk).]相似文献
Nerve gas mimic binding with Rhodamine B ethylenediamine (1) was studied in organic media. Binding of the nerve gas mimic, diethyl chlorophosphate (DCP), with the probe generated a non-fluorescent intermediate and a fluorescent product. Fluorescent and non-fluorescent products generated were identified using mass spectrometry and X-ray crystallography. Time-dependent density functional theory calculations were also used to investigate the electronic structure of the fluorescent probe in the ground and lowest lying π?→?π* singlet excited state. Though good agreement between theory and experiment can be obtained for the intense peak in the experimental spectrum using non-hybrid functionals, care must be taken when modelling these complexes due to the appearance of an n?→?π* transition that is too low in energy and appears to fall in the shoulders of the π?→?π* transitions.
The reaction of [W(CN)(8)](3-) with Ln(3+) and pyrazine in acetonitrile yielded a series of isostructural compounds formulated as Ln(H(2)O)(4)(pyrazine)(0.5)W(CN)(8) (Ln = La(1), Ce(2), Pr(3), Nd(4), Sm(5), Eu(6), Gd(7)). The Ln(iii) and W(v) centers in the structure are linked through cyanide groups to form two-dimensional (2D) layers, which are further pillared by pyrazine, generating 3D frameworks. The magnetic behavior for compounds 1-7 were driven by the lanthanide ions involved. The Ln(iii) and W(v) ions in compounds 2 and 5 are ferromagnetically coupled with magnetic ordering occurring at 2.8 K, comparable with magnetic ordering with the critical temperature of 1.9 K for compound 4. In addition, the antiferromagnetic interactions were observed in compounds 3 and 7, while no significant magnetic couplings were found in compounds 1 and 6. 相似文献
Co2Z hexaferrite materials possess intrinsically high permeability, zero field ferromagnetic resonance values (∼1 GHz), and have their magnetic orientation in the plane perpendicular to the c-axis. These characteristics make these materials practical for applications in low to mid ultra-high frequency and L-band microwave device designs. Due to the relatively large size of elements operating within these bands, it has become important to produce large amounts of Co2Z type hexaferrite materials. A modified co-precipitation method has been proposed to produce scalable quantities of high quality Co2Z hexaferrite particles, at ∼24 g/L. These particles have been thoroughly characterized by vibrating sample magnetometry (VSM) and X-ray diffraction (XRD) with regard to phase purity and magnetic properties. After formation and subsequent ball milling, to achieve single domain particles on the order of 0.5–2 um, particles were oriented and pressed into compacts inside a rotating field to ensure magnetization in plane. Samples then underwent VSM, XRD, and scanning electron microscopy to determine the orientation effect. In addition, the complex permittivity and permeability of these samples were measured as a function of applied field and processing conditions. The results show strong orientation in these compacts making them practical for a variety of device applications. 相似文献
Counting is one of the most basic procedures in mathematics and statistics. In statistics literature it is usually done via
the proportion estimation method. In this article we manifest a radically different counting procedure first proposed in the
late 1990’s based on the techniques of quantum computation. It combines two major tools in quantum computation, quantum Fourier
transform and quantum amplitude amplification, and shares similar structure to the quantum part of the celebrated Shor’s factoring
algorithm. We present complete details of this quantum counting algorithm and the analysis of its error distribution. Comparing
it with the conventional proportion estimation method, we demonstrate that this quantum approach achieves much faster convergence
rate than the classical approach. 相似文献
We performed molecular dynamics simulations to investigate hydrophobic interactions between two parallel hydrophobic plates immersed in water. The two plates are separated by a distance D ranging from contact to a few nanometers. To mimic the attractive hydrophobic force measurement in a surface force experiment, a driving spring is used to measure the hydrophobic force between two hydrophobic plates. The force-distance curves, in particular the force variations from spontaneous drying to hydrophobic collapse are obtained. These details are usually not accessible in the surface force measurement due to the unstable jump into contact. The length-scale effect on the hydrophobic drying during normal approach and the hydrophobic hysteresis during retraction has been studied. We find that the critical distance at which a spontaneous drying occurs is determined by the shorter characteristic dimension of the plate, whereas the hydrophobic hysteresis is determined by the longer characteristic dimension of the plate. The variations of the potential of mean force versus separation during approach and retraction are also calculated. The results show that water confined between two parallel hydrophobic plates is in a thermodynamic metastable state. This comparably high energy state leads to the spontaneous drying at some critical distance. 相似文献